Condoms are an imperfect tool. They slip. They break. They leak. In a laboratory setting, condoms are a practically perfect impenetrable barrier against viruses, but in the real world, they struggle to be invincible; condoms have an 80–85 percent reduction rate for HIV infection, and are even less effective against HPV and herpes. Wouldn’t it be great if we had a next-generation condom that not only provided a barrier against infection, but also actively destroyed viruses in semen, mucus or vaginal fluid?
Well now we do. Maybe.
On Sept 13, 2016, pharmaceutical company Starpharma announced that it has secured Health Canada approval for condoms imbued with VivaGel, a drug it says deactivates nearly all HIV, HPV and herpes viruses in the lab.
The condoms, marketed as LifeStyles Dual Protect, will hit shelves in Canada in 2017. The size of the asterisk hovering over the company’s health claims, however, should give pause to anyone hoping for a bulletproof defense against sexually transmitted infections (STIs).
Starpharma’s condoms are coated with an antimicrobial gel full of large organic polymer molecules called astodrimer, which bond to the outside of bacteria and viruses and deactivate them (since viruses aren’t precisely alive, “kill” isn’t quite the right word). In a petri dish, studies show the gel knocks out 99.9 percent of HIV, HPV and herpes virus. Starpharma has also dosed semen and vaginal fluid with the drug, and shown a similar reduction in viral load.
Based on this evidence, Starpharma hopes the condoms will provide a double barrier, both physical and pharmaceutical, against viral infection. The condoms have been available in Australia for two years, and during the Rio Olympics, the company even sent packages to Australian athletes to prevent the sexual transmission of Zika.
With all the research, publicity and media coverage the VivaGel condoms have received, you might think we would have a good idea of how well they actually prevent the spread of STIs. But you’d be wrong. There haven’t been any studies at all tracking the condoms’ effectiveness during actual sex.
Starpharma’s CEO Jackie Fairley stresses that the condoms don’t need epidemiological studies for approval because the company makes no claims about actual transmission reduction.
“The claim is not that it will prevent the transmission of infection from X to Y,” she says. “We’re not claiming actual prevention of disease. We’re claiming risk reduction. It’s an added benefit rather than absolute protection.”
What’s more, she says, it’s unlikely there will ever be a study on the actual effectiveness of VivaGel condoms. The problem is that, when used correctly, condoms are already pretty effective at preventing the spread of STIs, so a study to test the added benefit of VivaGel would require an extremely large number of participants to show any difference. That’s not a study Fairley thinks is feasible.
There’s a logical leap from a medication working in the lab to working in practice, but that leap doesn’t always hold up, says Dr Nathan Lachowsky, a researcher at the BC Centre for Excellence in HIV/AIDS and professor of public health at the University of Victoria.
“There are lots of things that have worked in a lab and not worked in real life, and lots of things that have worked in a lab and did work in real life,” he says. “But in this case, there’s a lack of evidence.”
VivaGel may be nearly perfectly effective in the lab, Lachowsky points out, but then so are normal latex condoms. Once used by consumers, we don’t know how VivaGel condoms will stand up to slips, breaks and leakage. We also don’t know if they will be effective against the spread of HPV and herpes, which can be transmitted by skin contact outside the area covered by a condom. It seems likely VivaGel will do some good, but how much is entirely conjecture.
More importantly, condom failure isn’t the main concern of doctors on the front lines of HIV prevention. Even people who use condoms rarely use them all the time, and research shows HIV-negative gay men don’t consistently use condoms during sex. That’s why the cutting-edge of HIV prevention is focused on PrEP (pre-exposure prophylaxis), PEP (post-exposure prophylaxis), treatment as prevention and rapid testing, techniques that work for those who use condoms and those who don’t. Tellingly, nobody at either the BC Centre for Excellence or the BC Centre for Disease Control has even heard of VivaGel condoms, despite their recent approval.
Lachowsky says the arrival of VivaGel condoms isn’t a bad thing, and he will always welcome new tools in the fight against HIV. Even if Starpharma’s condoms don’t work any better than conventional ones, he adds, the idea alone might convince more people to use them. And conventional condoms, the evidence shows, work beyond a doubt.
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